[INFO] fetching crate algen 0.2.0...
[INFO] checking algen-0.2.0 against try#4f260f0f20b3133d20cfb50353c0221943af5796+rustflags=-Dunmustuse_in_always_ok for pr-148577
[INFO] extracting crate algen 0.2.0 into /workspace/builds/worker-0-tc2/source
[INFO] started tweaking crates.io crate algen 0.2.0
[INFO] finished tweaking crates.io crate algen 0.2.0
[INFO] tweaked toml for crates.io crate algen 0.2.0 written to /workspace/builds/worker-0-tc2/source/Cargo.toml
[INFO] validating manifest of crates.io crate algen 0.2.0 on toolchain 4f260f0f20b3133d20cfb50353c0221943af5796
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+4f260f0f20b3133d20cfb50353c0221943af5796" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] crate crates.io crate algen 0.2.0 already has a lockfile, it will not be regenerated
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+4f260f0f20b3133d20cfb50353c0221943af5796" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc2/source:/opt/rustwide/workdir:ro,Z" "-v" "/var/lib/crater-agent-workspace/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/var/lib/crater-agent-workspace/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--user" "0:0" "--network" "none" "ghcr.io/rust-lang/crates-build-env/linux@sha256:4848fb76d95f26979359cc7e45710b1dbc8f3acb7aeedee7c460d7702230f228" "/opt/rustwide/cargo-home/bin/cargo" "+4f260f0f20b3133d20cfb50353c0221943af5796" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 60c45a83fa7b2bd4722dcc62c6a2975266a1012586b0e58f40fabc1f1a00244a
[INFO] running `Command { std: "docker" "start" "-a" "60c45a83fa7b2bd4722dcc62c6a2975266a1012586b0e58f40fabc1f1a00244a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "60c45a83fa7b2bd4722dcc62c6a2975266a1012586b0e58f40fabc1f1a00244a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "60c45a83fa7b2bd4722dcc62c6a2975266a1012586b0e58f40fabc1f1a00244a", kill_on_drop: false }`
[INFO] [stdout] 60c45a83fa7b2bd4722dcc62c6a2975266a1012586b0e58f40fabc1f1a00244a
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc2/source:/opt/rustwide/workdir:ro,Z" "-v" "/var/lib/crater-agent-workspace/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/var/lib/crater-agent-workspace/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=forbid -Dunmustuse_in_always_ok" "-e" "RUSTDOCFLAGS=--cap-lints=forbid" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--user" "0:0" "--network" "none" "ghcr.io/rust-lang/crates-build-env/linux@sha256:4848fb76d95f26979359cc7e45710b1dbc8f3acb7aeedee7c460d7702230f228" "/opt/rustwide/cargo-home/bin/cargo" "+4f260f0f20b3133d20cfb50353c0221943af5796" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 57d176046bf705003bdc51fc6d7943c0dc8e5a4322cf14c10e8fa15101f1c3b0
[INFO] running `Command { std: "docker" "start" "-a" "57d176046bf705003bdc51fc6d7943c0dc8e5a4322cf14c10e8fa15101f1c3b0", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.137
[INFO] [stderr]    Compiling crossbeam-utils v0.8.13
[INFO] [stderr]    Compiling memoffset v0.7.1
[INFO] [stderr]    Compiling crossbeam-epoch v0.9.12
[INFO] [stderr]    Compiling rayon-core v1.10.1
[INFO] [stderr]     Checking either v1.8.0
[INFO] [stderr]     Checking crossbeam-channel v0.5.6
[INFO] [stderr]     Checking crossbeam-deque v0.8.2
[INFO] [stderr]     Checking getrandom v0.2.8
[INFO] [stderr]     Checking num_cpus v1.14.0
[INFO] [stderr]     Checking rand_core v0.6.4
[INFO] [stderr]     Checking rand_chacha v0.3.1
[INFO] [stderr]     Checking rayon v1.6.0
[INFO] [stderr]     Checking rand v0.8.5
[INFO] [stderr]     Checking algen v0.2.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused import: `super::*`
[INFO] [stdout]    --> src/lib.rs:226:9
[INFO] [stdout]     |
[INFO] [stdout] 226 |     use super::*;
[INFO] [stdout]     |         ^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_imports)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `generation`
[INFO] [stdout]   --> src/lib.rs:89:9
[INFO] [stdout]    |
[INFO] [stdout] 89 |     for generation in 0..params.generations {
[INFO] [stdout]    |         ^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_generation`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `generation`
[INFO] [stdout]   --> src/lib.rs:89:9
[INFO] [stdout]    |
[INFO] [stdout] 89 |     for generation in 0..params.generations {
[INFO] [stdout]    |         ^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_generation`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: this type will no longer be must used: Result<String, Infallible>
[INFO] [stdout]   --> examples/hello_world/main.rs:90:16
[INFO] [stdout]    |
[INFO] [stdout] 90 |         return String::from_str(std::str::from_utf8(&output.to_vec()).unwrap()).unwrap();
[INFO] [stdout]    |                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: requested on the command line with `-D unmustuse-in-always-ok`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `algen` (example "hello_world") due to 1 previous error
[INFO] running `Command { std: "docker" "inspect" "57d176046bf705003bdc51fc6d7943c0dc8e5a4322cf14c10e8fa15101f1c3b0", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "57d176046bf705003bdc51fc6d7943c0dc8e5a4322cf14c10e8fa15101f1c3b0", kill_on_drop: false }`
[INFO] [stdout] 57d176046bf705003bdc51fc6d7943c0dc8e5a4322cf14c10e8fa15101f1c3b0